On 2/26/09 11:16 AM, "Maciej Stachowiak" <mjs@apple.com> wrote:
> Limiting the problem scope to non-visual media would, at first glance,
> violate our Media Independence and Accessibility design principles:
>
> http://www.w3.org/TR/html-design-principles/#media-independence
I don't see any relevance to this principle.
> http://www.w3.org/TR/html-design-principles/#accessibility
But on further reflection, one should see the parallels between what is
written in that second link:
"The image in an img may not be visible to blind users, but that is a reason
to provide alternate text(...)"
...and what we're dealing with here:
"The structure of a table may not be visible to blind users, but that is a
reason to provide summary information"
> If there is a specific reason that a feature only for non-visual media
> would be more effective than a feature for all media, perhaps because
> trying to be fully general hurts the non-visual case, then it might be
> appropriate to have a feature for non-visual users only.
There is a very specific use case for non-visual users that @summary serves.
When a screen-reader user navigates in table mode (at least in JAWS), the
user can hear the summary of each table in a document with one keypress.
This is an affordance equivalent to the visual user scanning the document
for navigation. Without it, those users need to enter a table and progress
linearly, cell by cell, until they determine whether the content of that
table is relevant to them or not. It's a very time-consuming process for
documents with lots of tables.
It would be simple to provide comparable functionality to sighted users, but
they don't experience anything near the same obstacles that screen-reader
users do.
Could this be done in a way that aids universal design? Sure: you could
present a UI component to users that mimics the feature that's so useful to
screen-reader users. The iCab browser did similar things with accesskey, for
example. Anyway, after 11 years of HTML 4.01, no user has found it valuable
enough to even extend a browser to offer that functionality to sighted
users, much less add a +1 to making @summary available to them.
It's all well and good that HTML5 has design principles. But it's
indefensible to claim accessibility as one of them, and then make (or
defend) a design decision that _reduces_ accessibility to people with
disabilities on the premise that able-bodied users are being left behind.
It's a red herring.
-
m